JP5411458B2 - 3D ultrasonic transmission beam forming - Google Patents

Description

  The present invention relates generally to ultrasound medical imaging systems, and more specifically to the segmentation of a plurality of transducer elements of an ultrasound probe for transmission of ultrasound signals into non-overlapping sub-apertures.

  The two main components of an ultrasound system are an ultrasound probe and a beamformer. The beamformer has focused and steered ultrasound energy transmitted and received by the probe for the collection of image data, one step of creating an image of anatomical content on the display It has become. Three-dimensional (3D) ultrasound imaging may be performed using a probe having a two-dimensional (2D) matrix array of transducer elements. In many systems, this component is used in both transmit and receive operations. In the current system, this dual operation of the transducer elements is achieved by multiplexing between the transmitter and receiver circuits in the system. Each channel in the probe is connected to the system using a single cable, and each channel may be used for both transmission and reception operations.

  The transducer elements are typically arranged in a 2D array that can be divided into multiple sub-apertures (or sub-arrays) for both transmit and receive operations by grouping a subset of transducer elements together. For example, each aperture may include at least one acoustic transducer element. The sub-aperture groupings may differ for transmission and reception. The layout and implementation of the sub-aperture for transmission and reception affects the image quality. Some of the probes utilize transmitters located within them, but this configuration can generate a large amount of heat. Thus, a transmission solution for a 2D array probe that can drive an array with a large number of elements (eg, approximately 2600 elements) by a relatively small number of system channels (eg, approximately 170 system channels). It is desirable to provide.

  Accordingly, there is a need for improved 2D array transmit beamforming for 3D ultrasound imaging with improved aperture sub-grouping without the limitations discussed above.

  In one embodiment, an ultrasound system includes a probe that includes a two-dimensional (2D) array of transducer elements that form an aperture having a plurality of receiving elements configured to receive ultrasound signals. The transducer elements form at least one transmit sub-aperture configured to be interconnected with a predetermined group of transducer elements within the aperture. The transmitter generates a transmit electrical signal, and at least one transmit sub-aperture processor (tx SAP) maps the transducer elements within a predetermined group of transducer elements to the transmitter in a transmit configuration based on the beam steering direction. Yes.

  In another embodiment, a method for transmitting an ultrasound signal using a 2D array of transducer elements includes at least one transmission sub-aperture with a predetermined group of transducer elements for transmitting ultrasound transmission signals. As well as forming at least two receive sub-apertures for receiving the ultrasound received signal. The at least one transmit sub-aperture and at least two receive sub-apertures are associated with a predetermined set of system channels. A delay is calculated for each of the transducer elements within the predetermined group of transducer elements, the delay being based at least on the steering angle associated with the transducer element and the transmission operation. At least a portion of the transducer elements within the predetermined group of transducer elements are connected to a predetermined system channel group based at least on a delay associated with the transducer element.

  In yet another embodiment, an ultrasound system includes a probe that includes a 2D array of transducer elements that form an aperture having a plurality of receiving elements configured to receive ultrasound signals. At least one configurable intersection switch has first and second sides and is interconnected on a first side with a predetermined group of transducer elements forming a transmission sub-aperture configured to transmit an ultrasound signal. ing. The system channel is configured to transmit at least a transmission signal and is interconnected on the second side with at least one configurable intersection switch. The at least one configurable intersection switch further comprises at least one switch associated with each of the transducer elements in the predetermined group of transducer elements and at least one of the transducer elements by the at least one configurable intersection switch. Is connected to one of the system channels. The sub-aperture processor (SAP) controller includes at least one configurable intersection for mapping each of the transducer elements within a predetermined group of transducer elements to a system channel in a transmission configuration based on a delay associated with the transmission signal. It is configured to control the switch.

  The foregoing summary, as well as the following detailed description of certain embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. Even when these drawings represent diagrams including functional blocks of various embodiments, it does not necessarily mean that these functional blocks are divided among hardware circuits. Thus, for example, one or more functional blocks (eg, processor or memory) may be implemented in the form of a single piece of hardware (eg, general purpose signal processor, random access memory, hard disk, etc.). Similarly, the program can be a stand-alone program, incorporated as a subroutine in the operating system, functioning in an installed software package, or the like. It should be understood that these various embodiments are not limited to the arrangements and instrumentality shown in the drawings.

  FIG. 1 shows a block diagram of an ultrasound system 100. The probe 106 is connected to the system 100 via a cable 142. The probe 106 has a transducer element 104 in a two-dimensional (2D) matrix array and can perform three-dimensional (3D) scanning. A system channel (not shown) may be present inside the cable 142 and may transmit transmit and receive signals to the probe 106. Alternatively, separate transmission and reception channels may be used. There is at least one transmit (tx) sub-aperture processor (SAP) 124 and one receive (rx) SAP 126 within the probe 106 for transmit and / or receive operations. In another embodiment, a single tx / rx SAP may facilitate both receive and transmit functions. SAP controller 128 is in communication with system processor 116 and / or beamformer 110. The SAP controller 128 further configures the transmit and receive sub-apertures by connecting specific transducer elements 104 to system channels (ie, transmit and receive channels) that are used to transmit ultrasound signals to the probe 106. To contact the SAP (s) 124 to do so. The SAP controller 128 can be implemented in the form of hardware, software, or a combination thereof, and may alternatively be located within the system 100, such as within the processor 116.

  The ultrasound system 100 includes a transmitter 102 that drives a transducer element 104 within the probe 106 to deliver a pulsed ultrasound signal into the body. The transmitter 102 is disposed outside the probe 106, such as inside a housing (not shown) that surrounds the internal components of the system 100. The beamformer 110 provides the transmitter 102 with information such as steering information provided as a steering signal, for example. This steering information may vary across the array of transducer elements 104. The SAP controller 128 further communicates to the tx SAP 124 and rx SAP 126 to control the local steering direction of individual sub-apertures (based on transmit and receive beam steering / focusing respectively).

  The transmitted ultrasonic signal is backscattered by structures in the body such as blood cells and muscle tissue, and an echo returned to the transducer element 104 is generated. The returned echo is converted to electrical energy received by the plurality of receivers 108 by the transducer element 104. The received signal is passed through a beamformer 110 that performs receive beamforming and outputs an RF signal. This RF signal is then passed through the RF processor 112. Alternatively, the RF processor 112 may include a complex demodulator (not shown) that demodulates the RF signal to form IQ data pairs representing the echo signal. The RF or IQ signal data may then be routed directly to the RF / IQ buffer 114 for temporary storage.

  User input 120, which can be configured as a user interface having a keyboard, mouse, trackball, control buttons, etc., includes ultrasound data including patient data, control of scanning parameter inputs, selection and identification of focal and interest areas, etc. 100 may be used to control the operation of 100 and may include the use of voice commands provided via microphone 144. Various alternative embodiments may include a set of user controls that may be configured to control the ultrasound system 100, such as a touch screen or part of a panel and / or user operable switches, buttons, etc. It may be provided as a manual input device. The set of user controls may be a manual operation type or a voice operation type.

  The ultrasound system 100 further processes the collected ultrasound information (ie, RF signal data and IQ data pairs) and a processor 116 (eg, an ultrasound information frame or volume for display on the display 118). Processor module). The display 118 may have a known resolution that can be defined in terms of pixels and other known parameters. The processor 116 is adapted to perform one or more processing operations according to a plurality of selectable ultrasound modalities on the collected ultrasound information. The collected ultrasound information may be processed in real time during the scanning session while receiving echo signals.

  Considering the system 100, it should be understood that the functionality is not limited to certain types of ultrasound systems. For example, the system 100 may be housed inside a cart-type system or may be implemented with a smaller portable system as discussed in FIG.

  FIG. 2 represents a 3D functional miniaturized ultrasound system 130 having a probe 132 configured to collect 3D ultrasound data. Although not shown, the probe 132 includes a 2D array of transducer elements 104 as discussed above in connection with the probe 106 of FIG. 1, and tx SAP 124 and rx SAP 126. A user interface 134 (which may include an integrated display 136) is provided for receiving commands from an operator. As used herein, “miniaturization” means that the ultrasound system 130 is a handheld or portable device, or can be carried in the hands of a staff, in a pocket, a document bag-sized case, or a rucksack. It means that it is configured. For example, the ultrasound system 130 may be a portable device having the size of a typical laptop computer having dimensions of, for example, a depth of approximately 2.5 inches, a width of approximately 14 inches, and a height of approximately 12 inches. is there. The ultrasound system 130 weighs about 10 pounds and may therefore be easily transportable by the operator. In addition, an integrated display 136 (e.g., an internal display) is provided and is configured to display medical images.

  The ultrasound data may be sent to the external device 138 via a wired or wireless network 140 (or a direct connection via, for example, a serial cable, parallel cable, or USB port). In some embodiments, the external device 138 may be a computer or workstation with a display. Alternatively, the external device 138 is a single external display or printer capable of receiving image data from the portable ultrasound system 130 and displaying or printing out images that may have a resolution that exceeds the integrated display 136. Sometimes.

  In another example, the ultrasound system 130 may be a 3D functional pocket size ultrasound system. As an example, a pocket-sized ultrasound system may be approximately 2 inches wide, approximately 4 inches long and approximately 0.5 inches deep, and weighs less than 3 ounces. A pocket-sized ultrasound system may include a display, a user interface (eg, keyboard), and an input / output (I / O) port (all not shown) for connection to a probe. It should be noted that various embodiments can be implemented in connection with miniaturized ultrasound systems that differ in size, weight and power consumption.

  FIG. 3 shows an aperture 170 extending across the plane of an ultrasound probe, such as the probe 106 of FIG. 1, consisting of a number of transducer elements 104 arranged in a 2D array. In this embodiment, the aperture 170 is divided into a plurality of receiving sub-apertures 172 represented in a triangular shape. In this example, there are 176 different receive sub-apertures 172. Each receive sub-aperture 172 includes 15 transducer elements 104 (FIG. 1). Each of the receive sub-apertures 172 is connected to one channel of the beamformer 110 via an rx SAP such as the rx SAP 126. During ultrasound reception, the signal received from the transducer element 104 passes through an independent delay (or phase shifter) within the rx SAP 26 and is a single output connected to the corresponding system channel. Are added to each other.

  FIG. 4 represents a transmit sub-aperture 180 and a portion 202 of the transmit sub-aperture composition in the form of a 2D array. This portion 202 represents a plurality of transmit sub-apertures 180 assembled in a non-overlapping rectangular sub-array. Each transmit sub-aperture 180 includes eight triangular receive sub-apertures 172, each having 15 transducer elements 104 as discussed above. Thus, the transmit sub-aperture 180 includes a total of 120 transducer elements 104 with 10 adjacent transducer elements 104 extending along a horizontal (azimuth) axis 181 and 12 along a vertical (longitudinal) axis 197. Adjacent transducer elements 104 are arranged to extend. Another configuration of receive sub-aperture 172 may be used. In transmit sub-aperture 180, multiple transmit sub-apertures are repeated throughout portion 202. Each of the transmit sub-apertures is connected to a predetermined group of transducer elements 104, and each of the transmit sub-apertures in portion 202 is connected to a different default group of transducer elements 104. For example, the transmission sub-aperture 180 is connected to a fixed group of 120 transducer elements 104 formed by the first and second element groups 198 and 200.

  During transmission of the ultrasonic pulse, the eight channels associated with the eight receive sub-apertures 182-194 drive the transducer element 104 in the transmit sub-aperture 180. As will be discussed below, each transducer element 104 can be connected to any of the eight channels, but is not limited by the configuration of this receive sub-aperture 182-194.

In one embodiment, the signals received from four adjacent receive subapertures 172 along the horizontal axis 181 such as the first, second, third and fourth receive subapertures 182, 184, 186 and 188 are four The fifth, sixth, seventh and eighth receive sub-apertures 190, 192, 194 and 196 are processed in the first integrated circuit including the rx SAP (not shown) and the first integrated circuit. Are processed in a second integrated circuit (not shown), which may be identical. The first to fourth reception sub-apertures 182 to 188 form a first element group 198, and the fifth to eighth reception sub-apertures 190 to 196 form a second element group 200. . The first and second element groups 198 and 200 are also referred to as element groups k ₁ and k ₁ +1, respectively, within the portion 202. The second transmit sub-aperture 204 within the portion 202 has first and second groups 206 and 208 having element groups k ₁ +2 and k ₁ +3, respectively.

FIG. 5 shows a block schematic diagram conceptually illustrating the use of an intersection switch to connect the transducer element 104 to a system channel during a transmission operation. It should be understood that the receiving circuit is omitted. First, second, third, and fourth intersection switches 210, 212, 214, and 216 are shown, each of which includes a plurality of switches (for interconnecting the transducer element 104 and the system channel). (Not shown). Each of the first through fourth intersection switches 210-216 is configured to have a first side 226 that interconnects transducer elements 104 and a second side 228 that interconnects system channels. It should be noted that although all of the intersection switches have not been discussed, this description applies to the remaining intersection switches. The first intersection switch 210 is connected to the first element group 198 (element group k ₁ ), and the second intersection switch 212 is connected to the second element group 200 (element group k ₁ +1). . Eight channels are connected to each of the intersection switches, which carry signals for each of the system transmitter 102 and receiver 108 of FIG. These channels include first and second channel groups 218 and 220 connected to first and second intersection switches 210 and 212 and third and fourth channel groups 222 and 224 being third and fourth. Illustrated as a group of four channels connected to intersection switches 214 and 216. As an example, a combination of the first and second intersection switches 210 and 212 may be referred to as a tx SAP 124, and a combination of the third and fourth intersection switches 214 and 216 may be referred to as a tx SAP 124. Yes, each of the tx SAPs 124 is connected to eight system transmission channels to drive 120 transducer elements 104.

  Each transducer element 104 may be connected to one, some, or any of the corresponding channels using an intersection switch. For a given transducer element 104 and a given transmit vector, only at most one of the intersection switches can be closed. In this example, there are sixty transducer elements 104 in the first element group 198, and eight channels in which both the transmission operation and the reception operation can be performed by the first and second channel groups 218 and 220. Is provided. Thus, for each of the transducer elements 104 (for a total of 480 switches), the ability to connect each of the transducer elements 104 to each of the channels within the first and second channel groups 218 and 220 within the intersection switch 210. There may be up to 8 switches to provide. For a given transmit vector, the intersection switch is programmed to select which of the 480 switches in the intersection switch to close. This selection may be based on the delay associated with the transducer element 104 (which will be discussed below). A maximum of 60 switches (one for each transducer element 104) will be closed simultaneously.

  Alternatively, an intersection switch having a smaller total number of internal switches may be provided. Thus, one or more transducer elements 104 can be attached to one or more channels, provided that the number of channels is less than eight. For example, two or four switches may be made available to connect to each of two or four channels rather than eight switches for each transducer element 104. In another example, a subset of the transducer elements 104 may be provided with a single switch so that the transducer elements 104 are always connected to the same channel when used for transmission. In this case, a plurality of switches may be provided in another transducer element 104. Reducing the number of switches by “sparsing” the intersection switches reduces the amount of silicon area required to create an integrated circuit.

  FIG. 6 shows an example of a transmission configuration. The aperture 420 is illustrated as having a 2D array of transducer elements 104. In this example, the 2D array comprises 60 × 48 transducer elements 104. The 2D array is divided into 24 transmit sub-apertures, each having a 2D array of 10 × 12 transducer elements 104, such as first, second, and third transmit sub-apertures 422, 424, and 426. ing. Not all of the transmit sub-apertures are identified by reference numbers.

  Transducer elements 104 within each of the transmit sub-apertures are connected to the system channel to form a transmit configuration based on the beam steering direction. This beam steering direction may be based on one or more focal points, and in this example the focal point is either straight down along the probe plane or straight with respect to the field of view of the probe. It has become. The transducer element 104 of the second transmit sub-aperture 424 is shown in more detail. Different sets of transducer elements 104 within the second transmit sub-aperture 424 are mapped to different channels within the eight system channels. For example, the first set 428, the second set 430, the third set 432, the fourth set 434, the fifth set 436, the sixth set 438, the seventh set 440, and the eighth set 442 of the transducer element 104 are the first, Each of the second, third, fourth, fifth, sixth, seventh and eighth system channels (not shown) can be mapped.

  FIG. 7 illustrates an aperture 450 having a transmission configuration that is mapped to steer the focus to one side. Again, the aperture 450 is separated into 24 transmit sub-apertures and a transmit sub-aperture 452 is shown. The beam steering direction is directed to the side of the probe 106 where the field of view is located. Transducer element 104 of transmit sub-aperture 452 is mapped to a system channel (not shown) in the transmit configuration as shown. The first set 454, the second set 456, the third set 458, the fourth set 460, the fifth set 462, the sixth set 464, the seventh set 466, and the eighth set 468 of the transducer element 104 are the first and second sets. , 3rd, 4th, 5th, 6th, 7th and 8th system channels.

  FIG. 8 represents a method for determining the mapping of a transducer element 104 to a channel during transmission. The method is performed for each transmit sub-aperture 180 and may be performed iteratively throughout the ultrasound inspection process to dynamically focus the ultrasound beam. At 270, processor 116 (see FIG. 1) calculates the delay for each transducer element 104. This delay may be calculated using well-known techniques and / or its transmission, such as based on focus, local steering angle or direction, and / or location within the aperture 170 (FIG. 3) of the probe 106. May be based on sub-aperture specific direction (ie beam steering) setup information. Alternatively, the delay may be calculated by the beamformer 110 and / or the sub-aperture controller 128. At 272, the processor 116 compares the delays to determine the maximum and minimum delays. At 274, processor 116 assigns maximum and minimum delays to two single channels, and at 276, processor 116 assigns intermediate delay values to the remaining channels.

  For example, the processor 116 may determine a delay for each of the transducer elements 104 within the first group of elements 198 of FIG. Just as an example, the minimum delay may be zero, and may be assigned to the first channel within the first channel group 218. The maximum delay may be 500 nanoseconds and may be assigned to a fourth channel within the second channel group 220. The intermediate delay value is based on the maximum and minimum delays and may be determined using uniform quantization, for example. This intermediate delay value is then assigned to the remaining six channels. It should be understood that any delay can be assigned to any channel, and is not limited to the ordering examples discussed herein.

  In another embodiment, the transducer element 104 pair-to-channel assignment and channel delay distribution (determined at 274 and 276) may be set according to the optimization criteria minimization. This criterion may be an average value of the mean square delay error or a minimization of the maximum sidelobe level of the transmit beam profile.

  At 278, processor 116 compares the delay of each transducer element 104 with each of the eight delays assigned to the eight channels and determines the minimum magnitude of the delay error for each transducer element 104. At 280, the processor 116 determines whether load balancing should be performed to minimize channel-to-channel variation. Some of the eight channels within the first and second channel groups 218 and 220 are assigned more transducer elements 104 compared to other channels, thereby for a given transmission vector. The electrical load for different transmission channels may not be the same. The system transmitter 102 has a finite output impedance, and different loads on each channel may cause some additional amplitude and / or delay variation. The series resistance of the probe cable 142 can also cause similar errors if load balancing is not performed. Thus, the method returns to 274 and / or 276 to modify the delay value assigned to one or more channels and to minimize the amount of delay error for each transducer element 104 based on the adjusted delay value. May be determined.

  At 282, the sub-aperture controller 128 programs or controls the intersection switch 210 to connect or map the transducer element 104 to the corresponding channel that provides the minimum absolute delay error based on information from the processor 116. As a result, a transmission configuration of the transmission sub-aperture is formed. Each transmit sub-aperture may have a different transmit configuration, and the transmit configuration may change from beam to beam, or change over time based on operator input such as different focus with respect to the transmit sub-aperture. is there. Continuing with the above example, the cross point switch 210 causes each of the transducer elements 104 in the first element group 198 to be one of the channels within the first and second channel groups 218 and 220 during a transmission operation. Programmed to connect. Optionally, the intersection switch 210 may not connect all of its transducer elements 104 during each transmission operation. Transmit configuration information is communicated to beamformer 110 and / or transmitter 102, such as communicating to transmitter 102 the delay assigned to each of the system channels.

  Typically, a transmission vector having a small steering angle has a small delay error. The magnitude of the delay error may increase as the amount of steering increases. To improve the beam profile for a transmit beam with a larger steering angle, the maximum delay value may be constrained to, for example, two periods of the transmitting center frequency. A transducer element 104 having a greater delay can be “wrapped” in this region by adding or subtracting a time corresponding to one period of the center frequency to preserve the desired phase adjustment relationship for the waveform. There is. Alternatively, the transducer element 104 having a relatively very large delay during transmission may be turned off by assigning the transducer element 104 to any channel. However, this causes a certain amount of sparseness during transmission. This tooth loss can be minimized, but may occur across the array surface or the entire aperture 170 of the probe 106 with respect to some spatial direction for some of the transmit sub-apertures 180.

  Further, each switch element in the intersection switch 210 may have a finite on-resistance. This resistance may be selected to be well below the expected electrical load (the sum of the transducer element electrical impedance and interconnect capacitance). This minimizes heat generation and improves manufacturing consistency. Furthermore, when the transmission signal is composed of a sine line burst at a center frequency f0 containing a relatively small amount of harmonics such as 2 * f0, 3 * f0, 4 * f0, etc., the power in the probe Loss can be reduced.

  Delay error is a problem both for different transmission channels within one transmission vector and between different transmission vectors. For example, if the transmit vector is perpendicular to the surface of the probe 106 with a focal point of infinity, all of the transducer elements 104 will have the same delay, such as zero delay. In this case, substantially the same signal is assigned to all eight transmission channels within the first and second channel groups 218 and 220, and the 120 transducer elements 104 are connected to one channel and remain. Instead of leaving the seven channels unused, it is desirable to connect 15 transducer elements to each of the eight channels. In this example, the load balance adjustment (280 in FIG. 8) may be performed by redistribution of transducer elements 104 between channels. In another embodiment, different intermediate delays may be selected to perform reallocation.

  The large size of the transmission sub-aperture 180 compared to the reception sub-apertures such as the first to eighth reception sub-apertures 182 to 196 of FIG. 4 helps to reduce the delay error associated with the transducer element 104 during transmission. Sometimes. A typical receive sub-aperture size is in the range of 15-25 of the transducer elements 104, while the transmit sub-aperture 180 in one embodiment has 120 transducer elements 104. In one embodiment, one intersection switch may span the entire array to connect all of the transducer elements 104 to all of the channels.

  In some embodiments, it may be desirable to partition the transmitting electronics in the same way as the receiver electronics. This is possible even if one transmit sub-aperture spans two receive ASICs. For example, returning to FIG. 4, as discussed above, the first through fourth receive sub-apertures 182-188 are processed by the first receive ASIC, and the fifth through eighth receive sub-apertures 190-196 are the first ones. Processed by two receiving ASICs. FIG. 5 shows how the pairs of transmit ASICs, each containing one 8 × 15 intersection switch, can be interconnected to obtain the topology of FIG.

  FIG. 9 depicts a transmit / receive architecture 300 for tx SAP using an intersection switch matrix 310 with first, second, third, and fourth intersection switches 360, 362, 364, and 366. First, second, third and fourth rx SAPs 302, 304, 306 and 308 are illustrated. Architecture 300 includes only half of the transmitting SAPs. The first, second, third and fourth input transmission / reception switching (t / r) switches 312, 314, 316 and 318 are connected to the first to fourth rx SAPs 302 to 308 by reception input lines 328, 330, 332 and 334, respectively. Connected to each of the inputs. The first, second, third and fourth output t / r switches 320, 322, 324 and 326 are respectively connected to the outputs of the first to fourth rx SAPs 302 to 308 by receive output lines 336, 338, 340 and 342, respectively. It is connected to the. During transmission, the first, second, third and fourth input t / r switches 312 to 318 and the first to fourth output t / r switches 320 to 326 are connected to the first to fourth rx SAPs 302 to 308, respectively. The first and fourth rx SAPs 302 to 308 are protected from the high voltage transmission pulse. During the reception period, the input and output t / r switches 312 to 326 are closed. During reception, all switches within the intersection switch matrix 310 are opened so that the rx SAP output is not shorted.

  Intersection switches 360-366 for the case where the cfg0, cfg1, cfg2, and cfg3 inputs for each of the rx SAPs 302, 304, 306, and 308 are controlled using, for example, a shift register chain (which may use another system architecture). The internal beamformer settings are shown in FIG. Each of the switches in the intersection switch 360 to 366 of one ASIC is assigned to one bit of the shift register, and the opening or closing of the switch is determined by the value of the bit.

  FIG. 10 illustrates how the functionality of the architecture 300 of FIG. 9 is divided into two parts, such as tx SAP 350 and rx SAP 352, for example. In one embodiment, tx and rx SAPs 350 and 352 are formed on two single silicon dies. The tx SAP 350 is typically formed using a silicon process with high voltage capability (typical transmit pulses are +/− 50 to 100 volts), while the rx SAP 352 is formed with a standard low voltage silicon process. May be. The two dies may then overlap each other. Alternatively, a single die configuration based on silicon processing that can handle high voltage, low noise analog designs as well as digital control may be possible. Optionally, digital control electronics may be added as a third die in the stack.

  FIG. 11 represents the superposition of the tx and rx SAP dies 354 and 356. This superposition configuration is compact and reduces the number of off-chip connections required. For example, 15 receive input lines 328-334 (see FIG. 9) and receive output lines 336-342 are connected only between tx and rx SAP dies 354 and 356, thereby leading to another integrated circuit (IC). It is possible to avoid one or more outer connections.

  Returning to FIG. 9, in one embodiment, the first to fourth input t / r switches 312 to 318, the first to fourth rx SAPs 302 to 308 and the first to fourth output t / r switches 320 to 326 are provided. May be removed. In this example, the first to fourth intersection switches 360 to 366 are bidirectional switches that connect the selected group of transducer elements 104 to the system transmitter 102 and the receiver 108 during both the transmission operation and the reception operation. Will be used. Therefore, fewer electronic circuits are required in this embodiment.

FIG. 12 shows an example of connecting the system channel to the transmission and reception sub-apertures using an intersection switch for each of the transmission operation and the reception operation. Optionally, a preamplifier 370 may be placed between the intersection switches 372 and 374 and the channel group 376. Transmit / receive switches 378 and 380 may be placed on either side of this optional preamplifier 370 and may be open during a transmit operation and closed during a receive operation. When receiving the signal, the intersection switch 372 connects the transducer element 104 in the reception sub-aperture including the element group k1 to _one of the _first to fourth channels (for example, the first channel 382). And the intersection switch 374 may be programmed to connect the transducer element 104 within the receiving sub-aperture with element group k ₁ +1 to, for example, the second channel 384. The intersection switches 372 and 374 may use a setting reception configuration different from the transmission configuration in order to assign the transducer element 104 to a designated channel during a reception operation.

  FIG. 13 illustrates an embodiment of four transmit sub-aperture configurations that can be used for steering an ultrasonic beam during transmission. The first, second, third and fourth transmission configurations 230, 232, 234 and 236 are represented. The transmission configuration may be selected based on at least a local steering direction in which each transmit sub-aperture steers the beam in the desired direction. In one embodiment, each group of four triangular receive sub-apertures may be connected to four system channels.

  Returning again to FIG. 4, the transmission sub-aperture 180 is divided into first and second element groups 198 and 200 arranged in a horizontal superposition configuration. The configuration of FIG. 4 is illustrated as a first transmission configuration 230 in which a first element group 238 and a second element group 240 are horizontally superimposed on each other. The second transmission configuration 232 divides the transmission sub-aperture into first and second element groups 242 and 244 arranged side by side. The third transmission configuration 234 divides the transmission sub-aperture into first and second element groups 246 and 248 diagonally, and the fourth transmission configuration 236 diagonally divides the transmission sub-aperture into first and second elements. It is divided into two element groups 250 and 252. By way of example only, the first transmission configuration 230 may steer the beam up and down with respect to the surface of the figure, and the second transmission configuration 232 may steer the beam in the left and right direction and the third transmission Configuration 234 may steer the beam in the direction of upper left corner / lower right corner, and fourth transmission configuration 236 may steer the beam in the direction of upper right corner / lower left corner.

  FIG. 14 illustrates the transmission aperture 254 in a position where the focal point 256 is outward from the plane of the illustrated transmission aperture 254 and toward the upper right corner of the transmission aperture 254. In other words, the illustrated focal point 256 is a projection of the actual focal point. The transmission aperture 254 is divided into a plurality of transmission sub-apertures each having first and second transducer element groups. Shown is a region passing through a transmission aperture 254 having the same delay by a plurality of delay lines 258, the direction of the delay line being dependent on the selected steering direction and focus for that transmit beam. In this example, each of the transmit sub-apertures is individually configured to achieve the desired steering for focus 256. For example, the first sub-aperture 260 is configured with a fourth transmission configuration 236, and the second sub-aperture 262 is configured with a second transmission configuration 232.

  FIG. 15 represents a hardware implementation for the embodiment of FIGS. A smaller intersection switch matrix 390 may be used and may be preceded by a multiplexer matrix 392 programmed according to the desired group configuration (first transmission configuration 230, second transmission configuration 232, etc.). The transmit current flowing through the multiplexer matrix 392 is significantly larger than the current flowing through the intersection switch matrix 390. Accordingly, the on-resistance of the multiplexer matrix 392 may be smaller (eg, at least a quarter) than the on-resistance of the intersection switch within the intersection switch matrix 390. The channel-to-channel delay assignment and switch programming of the transducer element 104 can be determined as described above in the connection of FIG.

  FIG. 16 represents an embodiment where the transmit sub-aperture 400 comprises a plurality of square receive sub-apertures 402. In this example, each transmit sub-aperture 400 has four receive sub-apertures 402. The transmit sub-aperture 400 may be divided into first and second element groups 404 and 406 as discussed above in FIG. The first and second element groups 404 and 406 are illustrated with a first transmission configuration 230 (see FIG. 13) and may be configured with a second transmission configuration 232.

  The technical effect of at least one embodiment is to divide the transducer element of the probe into non-overlapping rectangular transmit sub-apertures and steer the transmit beam in the desired direction during transmit operations. Each transmit sub-aperture may include a plurality of receive sub-apertures. The transmission sub-apertures can be individually configured with different transmission configurations. In order to reduce the delay error, the transducer elements in each transmission sub-aperture are mapped to system channels based on the delay of the transducer elements.

It should be understood that the above description is illustrative and not restrictive. For example, the above-described embodiments (and / or aspects thereof) may be used in combination with each other. In addition, many modifications may be made without departing from the spirit of the invention to adapt specific situations and materials to the teachings of the invention. The material dimensions and types described herein are intended to define the parameters of the present invention, which are by no means limiting and are exemplary of embodiments. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims define. In the appended claims, the expressions “including” and “in what” are used in conjunction with the corresponding expressions “comprising” and “where”. Is used as a plain English expression for. Further, in the appended claims, the “first”, “second” and “third” other expressions are merely used for labeling and numerical requirements for the subject matter. It is not intended to impose. Further, the limitations of the appended claims are not described in means-plus-functional form, and 35 U.S. Pat. S. C. 112, nor is it intended to be construed under the sixth paragraph (however, with respect to additional structure following the expression “means for” by limitation of the scope of the claims) Except when explicitly using the description of function exclusion). Further, the reference numerals in the claims corresponding to the reference numerals in the drawings are merely used for easier understanding of the present invention, and are not intended to narrow the scope of the present invention. Absent. The matters described in the claims of the present application are incorporated into the specification and become a part of the description items of the specification.

1 is a block diagram of an ultrasound system formed in accordance with one embodiment of the present invention. 1 is a diagram of a miniaturized ultrasound system formed in accordance with one embodiment of the present invention having a probe configured to collect ultrasound data. FIG. FIG. 3 is a diagram illustrating an aperture of an ultrasonic 2D array including transducer elements formed according to an embodiment of the present invention. FIG. 4 is a diagram illustrating a portion of multiple transmit sub-apertures and transmit sub-aperture organizations formed in accordance with an embodiment of the present invention. FIG. 3 is a block schematic diagram illustrating connection of transducer elements using intersection switches for system channels connected to a transmitter according to one embodiment of the present invention. It is a figure showing an example which maps the transmission structure of the aperture of the probe and transmission sub-aperture inside the aperture according to one embodiment of the present invention. It is a figure showing another example of mapping of the transmission structure by one Embodiment of this invention. 4 is a flow diagram of a method for determining a mapping for transducer elements and channels during transmission according to an embodiment of the invention. 2 is a block schematic diagram of an input / output architecture for a transmit sub-aperture processor (tx SAP) using an intersection switch matrix with switches formed in accordance with an embodiment of the invention. FIG. FIG. 10 is a block schematic diagram illustrating the separation of the architecture of FIG. 9 into transmit and receive SAPs according to one embodiment of the present invention. FIG. 3 is an elevational view illustrating a superposition of transmission and reception SAPs according to an embodiment of the present invention. It is a block schematic diagram showing the intersection switch according to one embodiment of the present invention being used in both the transmission operation and the reception operation. FIG. 4 is a diagram illustrating four types of sub-aperture configurations of transmission sub-apertures that can be used for ultrasound beam steering during transmission in accordance with one embodiment of the present invention. FIG. 6 illustrates a transmission aperture according to one embodiment of the present invention, along with corresponding delay lines that indicate focus projection and transducer element delay. FIG. 15 is a block schematic diagram illustrating a hardware implementation of the transmission sub-aperture configuration of FIGS. 13 and 14 formed in accordance with an embodiment of the present invention. FIG. 4 is a diagram illustrating a transmission sub-aperture having a plurality of square reception sub-apertures according to an embodiment of the present invention.

Explanation of symbols

100 Ultrasonic System 102 Transmitter 104 Transducer Element 106 Probe 108 Receiver 110 Beamformer 112 RF Processor 114 RF / IQ Buffer 116 Processor 118 Display 120 User Input 124 Transmit Sub-Aperture Processor (tx SAP)
126 Receive Sub-Aperture Processor (rx SAP)
128 SAP Controller 130 Miniaturized Ultrasound System 132 Probe 134 User Interface 136 Integrated Display 138 External Device 140 Network 142 Cable 144 Microphone 170 Aperture 172 Receiving Sub-Aperture 180 Transmitting Sub-Aperture 181 Horizontal Axis 182 Receiving Sub-Aperture 184 Receiving Sub Aperture 186 Reception sub-aperture 188 Reception sub-aperture 190 Reception sub-aperture 192 Reception sub-aperture 194 Reception sub-aperture 196 Reception sub-aperture 197 Vertical (vertical) axis 198 First element group 200 Second element group 202 Transmission sub-aperture composition Part 204 Transmission sub-aperture 206 Second element group 208 First element group 210 Intersection switch 212 Intersection Switch 214 intersection switch 216 intersection switch 218 first channel group 220 second channel group 222 third channel group 224 fourth channel group 226 first side 228 second side 230 first transmission configuration 232 second Transmission configuration 234 third transmission configuration 236 fourth transmission configuration 238 first element group 240 second element group 242 first element group 244 second element group 246 first element group 248 second element Group 250 first element group 252 second element group 254 transmit aperture 256 focus 258 delay line 260 first sub-aperture 262 second sub-aperture 300 transmit / receive architecture 302 rx SAP
304 rx SAP
306 rx SAP
308 rx SAP
310 intersection switch matrix 312 input t / r switch 314 input t / r switch 316 input t / r switch 318 input t / r switch 320 output t / r switch 322 output t / r switch 324 output t / r switch 326 output t / r r switch 328 reception input line 330 reception input line 332 reception input line 334 reception input line 336 reception output line 338 reception output line 340 reception output line 342 reception output line 350 tx SAP
352 rx SAP
354 tx SAP die 356 rx SAP die 360 Intersection switch 362 Intersection switch 364 Intersection switch 366 Intersection switch 370 Preamplifier 372 Intersection switch 374 Intersection switch 376 Channel group 378 Transmit / receive switch 380 Transmit / receive switch 382 First channel 382 First channel Two channels 390 Intersection switch matrix 392 Multiplexer matrix 400 Transmit sub-aperture 402 Square receive sub-aperture 404 First element group 406 Second element group 420 Aperture 422 Transmit sub-aperture 424 Transmit sub-aperture 426 Transmit sub-aperture 428 First set Transducer element 430 Second set of transducer elements 432 Third set of transducer elements 434 Fourth set Transducer element 436 Fifth set of transducer elements 438 Sixth set of transducer elements 440 Seventh set of transducer elements 442 Eighth set of transducer elements 450 Aperture 452 Transmit sub-aperture 454 First set of transducer elements 456 Second set of transducer elements 458 Third set of transducer elements 460 Fourth set of transducer elements 462 Fifth set of transducer elements 464 Sixth set of transducer elements 466 Seventh set of transducer elements 468 Eighth set of transducer elements

Claims (10)

A probe (106) including a two-dimensional (2D) transducer element array (104) forming an aperture (170) having a plurality of receiving elements configured to receive an ultrasound signal, the transducer (106) A probe (106) forming at least one transmit sub-aperture within the aperture (170) configured to be interconnected with a predetermined group of transducer elements (104); ,
A transmitter (102) for generating a transmitted electrical signal;
At least one transmit sub-aperture processor comprising an intersection switch for mapping the transducer elements (104) within the predetermined set of transducer elements (104) with a transmitter (102) in a transmit configuration based on beam steering direction ( tx SAP) (124),
A plurality of system channels interconnected with a transmitter (102) and a cross point switch to transmit transmission signals therebetween;
An SAP configured to control an intersection switch to select a transducer element (104) to be driven by one of the plurality of system channels based on a transmission configuration within the predetermined group of transducer elements (104). A controller (128);
With
The plurality of receiving elements are configured to form a receiving sub-aperture, wherein the at least one transmitting sub-aperture comprises at least two adjacent receiving sub-apertures;
An ultrasound system (100), wherein individual transducer elements (104) within the predefined group of transducer elements (104) can be connected to any of the plurality of system channels using the intersection switch. A system channel interconnected with the transmitter (102) for transmitting transmission signals;
A processor (116) configured to determine a delay associated with each of the transducer elements (104) within the predetermined group of transducer elements (104), the delay being based at least on a beam steering direction; The at least one transmit sub-aperture processor (tx SAP) (124) determines at least one of the transducer elements (104) within a predetermined group of transducer elements (104) of the system channels based on the delay. A processor (116) configured to allocate to one channel;
The ultrasound system (100) of claim 1, further comprising: A beamformer (110) for providing a steering signal to the transmitter (102);
The ultrasound system (100) of claim 1 or 2, wherein each of the receive sub-apertures is connected to one channel of the beamformer (110). Further, the SAP configured to divide the receiving elements of the at least one transmitting sub-aperture into two groups of elements (198, 200) oriented relative to each other by one of horizontal, vertical and diagonal. comprises control device (128), the two element groups (198, 200) forms a different transmission configuration for steering a transmit signal in different directions, according to any one of claims 1 to 3 Ultrasound system (100). The intersection switch has a plurality of switches, each switch is associated with only one of the individual transducer elements in the predetermined set of transducer elements (104) (104), according to claim 1 to 4 An ultrasound system (100) according to any of the above. The ultrasound system (100) of any of the preceding claims, wherein the SAP controller (128) is disposed within the probe (106). The ultrasound system (100) according to any of the preceding claims, wherein the SAP controller (128) is located outside the probe (106). A probe (106) including a two-dimensional (2D) transducer element array (104) forming an aperture (170) having a plurality of receiving elements configured to receive an ultrasonic signal;
At least one configurable element having a first and second side and interconnected at said first side with a predetermined group of transducer elements forming a transmission sub-aperture configured to transmit an ultrasound signal An intersection switch,
A system channel configured to communicate at least a transmission signal and interconnected with the at least one configurable intersection switch on the second side;
Configured to control at least one configurable intersection switch to map each of the transducer elements within a predetermined group of transducer elements to a system channel in a transmission configuration based on a delay associated with a transmission signal. A sub-aperture processor (SAP) controller;
With
The transmit sub-aperture comprises at least two adjacent receive sub-apertures;
The at least one configurable intersection switch has a plurality of switches, each of the plurality of switches being associated with a respective corresponding transducer element in a predetermined group of transducer elements, the transducer being configured by the at least one configurable intersection switch. An ultrasound system (100) that connects at least one of the elements to one of the system channels. The transmission sub-aperture is divided into at least first and second reception sub-apertures, wherein the first and second reception sub-apertures are the first of a plurality of transducer elements in a predetermined group of transducer elements that receive an ultrasonic signal. The ultrasound system (100) of claim 8, comprising the first and second predetermined subsets. A probe (106) including a two-dimensional (2D) transducer element array (104) forming an aperture (170) having a plurality of receiving elements configured to receive an ultrasound signal, the transducer (106) A probe (106) forming at least one transmit sub-aperture within the aperture (170) configured to be interconnected with a predetermined group of transducer elements (104); ,
A transmitter (102) for generating a transmitted electrical signal;
At least one configurable intersection switch interconnecting the predetermined group of transducer elements and the transmitter (102);
A plurality of system channels interconnected with a transmitter (102) and a cross point switch to transmit transmission signals therebetween;
With
The transmit sub-aperture comprises at least two adjacent receive sub-apertures;
At least one transducer element in the predefined group of transducer elements is connected to a different system channel than the at least one other transducer element in the predefined group of transducer elements using the at least one configurable intersection switch. An ultrasound system (100).

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